Prior to the present invention, there have been in existence electrically driven scraper vibration means of various structures as well as recently an air driven vibration means for the purpose of a dental scraper.
With the .[.selenoid.]. .Iadd.solenoid .Iaddend.type electrically actuated type scrapers, there have existed undesirable features and disadvantages such as for example the undesirability of using any form of electricity in the vicinity of moisture which could accidentally .[.braing.]. .Iadd.bring .Iaddend. about an electrical shock to a dental patient, as well as the well-known fact that the conventional electrically actuated scrapers currently available are plagued with the problem of cooling necessitating the flow of cooling water therethrough -- which flow of water not only complicates the mechanism but additionally further increases the real possibility of accidental shock as parts become worn and/or aged at which time the possibility of short-circuits is increased. Also, by virtue of the necessity of the electrically driven mechanisms and together therewith the cooling thereof with water, the structures are bulky and cumbersome in the handling thereof and additionally are extremely costly in the many parts and cost thereof plus the labor of manufacture being costly and time-consuming, resulting in a high required price to the dentist.
Air driven motors and vibrators heretofore known also have been of a complex nature and bulky, but more importantly have been subject .[. to rapid.]. to rapid deterioration and/or wear of the parts thereof, particularly the bearing surfaces -- requiring repeated and frequent replacement of such surfaces as well as also being complicated in the manufacture thereof and not nearly so efficient as the electrically actuated mechanisms, for example in the rate and/or magnitude of vibrations attainable.
Also, with the previously electrically actuated as well as the previously air vibrated scrapers, it has not been possible to obtain the desired high level of vibration with the accompanying high scraping efficiency and speed thereof without simultaneously being plagued by the problems and disadvantages noted above.